3-Phenylbenzofuranalkanoic acids and -alkenoic acids and certain derivatives thereof have been reported, for example in U.S. Pat. Nos. 3,682,976 and 3,862,134 as having antiinflammatory acitivity. The compound 2-nitro-3-phenylbenzofuran has been reported, although no physiological activity has been reported prior to the present invention. Certain neutral 2-nitrobenzofurans are known as antibacterial agents, for example, see French Pat. No. 2,081,585 and several publications by Rene Royer, et al. Acidic compounds combining the structural features of the compounds of the present invention have not previously been described.